1. Field
The present application relates generally to methods and systems that facilitate the administration and imaging of cells, and more particularly to facilitate the administration and imaging of stem cells to target tissues in the context of stem cell therapy.
2. Description of the Related Art
The scope of human disease that involves loss of or damage to cells is vast and includes, but is not limited to, ocular disease, neurodegenerative disease, endocrine diseases, cancers, and cardiovascular disease. Cellular therapy involves the use of cells, and in some cases stem cells to treat diseased or damaged tissues. It is rapidly coming to the forefront of technologies that are poised to treat many diseases, in particular those that affect individuals who are non-responsive to traditional pharmacologic therapies.
In fact, many diseases that are candidates for application of cellular therapy are not fatal, but involve loss of normal physiological function. For example, ocular diseases often involve functional degeneration of various ocular tissues which affects the vision, and thus the quality of life of numerous individuals.
The mammalian eye is a specialized sensory organ capable of light reception and is able to receive visual images. The retina of the eye comprises photoreceptors that are sensitive to various levels of light and interneurons that relay signals from the photoreceptors to the retinal ganglion cells, which transmit the light-induced signals to the brain. The iris is an intraocular membrane that is involved in controlling the amount of light reaching the retina. The iris comprises two layers (arranged from anterior to posterior), the pigmented fibrovascular tissue known as a stroma and pigmented epithelial cells. The stroma connects a sphincter muscle (sphincter pupillae), which contracts the pupil, and a set of dilator muscles (dilator pupillae) which open it. The pigmented epithelial cells block light from passing through the iris and thereby restrict light passage to the pupil.
Numerous pathologies can compromise or entirely eliminate an individual's ability to perceive visual images, including trauma to the eye, infection, degeneration, vascular irregularities, and inflammatory problems. The central portion of the retina is known as the macula, which is responsible for central vision, fine visualization and color differentiation. The function of the macula may be adversely affected by age related macular degeneration (wet or dry), diabetic macular edema, idiopathic choroidal neovascularization, high myopia macular degeneration, or advanced retinitis pigmentosa, among other pathologies.
Age related macular degeneration typically causes a loss of vision in the center of the visual field (the macula) because of damage to the retina. It is a major cause of visual impairment in older adults (>50 years). Macular degeneration occurs in “wet” and “dry” forms. In the dry form, cellular debris (drusen) accumulates between the retina and the choroid, which puts pressure on the retina, possibly leading to retinal detachment and loss of vision. In the more severe wet form, newly formed blood vessels from the choroid infiltrate the space behind the macula, which causes death of photoreceptors and their supporting cells. In conjunction with the loss of functional cells in the eye, the newly formed blood vessels are fragile and often leak blood and interstitial fluid, which can further damage the macula.
While diseases that cause damage to specific cells or tissues are clear candidates for cellular therapy, there remains a need in the art for methods and systems to improve the efficacy of cellular therapy by monitoring cells that have been placed on a substrate and monitoring cells implanted into the body.